[ipoulin]

I just got off the phone from my dealer and the word, per what they know, is that 2003 American Cooper CVTs cannot have the "virtual shifting points" removed from the program, allowing it to rev up to 4000 and remain there, as per a euro-CVT.

Has anyone in the US had any luck in getting the 'virtual shifting points' feature turned off?

Ian Poulin
Boston, Ma.

[cooper4us]

Interesting question. can you post this on the CVT driving technique thread?

[nfo]

i didn't know that was possible!
that would be really wicked though!

[nonsequitur]

Does this statement mean that the CVT in other markets does NOT have the "shifting" behavior we see in the US? Which markets are different?

Does anyone know where this was discussed? I distinctly remember, but cannot now locate, an article or thread that confirms this "shifting" was a decision by BMW/MINI.

[Paul]

UK CVT's 'shift'....

[cooper4us]

Wait a minute...are we talking about the "Shifting" built into the Steptronic mode program or "Shifting" felt on Normal drive mode???

CVTs for the US and Canadian market do not have artificial "Shifting" feeling built into them on either Normal or Sport Modes, only on Steptronic to simulate the 6-speed semi-manual gear shift change.


Otherwise, our CVT exhibits continously acceleration with no feeling of any shifting points whatsoever on Normal or SD modes.

Let's establish this difference to avoid topic confusion.

[cooper4us]

Quote:

Originally posted by Paul Mullett
UK CVT's 'shift'....

You mean in normal mode?????


I guess or Euro friends are the ones with the "Americanized" CVTs, because mine does not have any shifting pattern feeling at all on Normal or SD modes. Only on Steptronic.

[ipoulin]

I am talking about CVT in either D or SD mode; not in steptronic mode. My knowledge of the CVT in europe is the car, once its going will rev up to 4000RPM and stay there; keeping the same RPM as you accelerate/de-accelerate.

In the US (Well, Boston at least which is all that really counts anyhow), in D or SD mode, the RPM will vary and see a rpm drop at points of the acceleration.

I would like to get it to the first mode, mentioned.

[Paul]

Quote:

Originally posted by ipoulin
I am talking about CVT in either D or SD mode; not in steptronic mode. My knowledge of the CVT in europe is the car, once its going will rev up to 4000RPM and stay there; keeping the same RPM as you accelerate/de-accelerate.

In the US (Well, Boston at least which is all that really counts anyhow), in D or SD mode, the RPM will vary and see a rpm drop at points of the acceleration.

I would like to get it to the first mode, mentioned.

In the UK, in D or SD, the car will 'shift' up a gear when you rev up to the limit.

[cooper4us]

First off, I would hate to drive a car running at 4,000 RPM and staying there all the time. Great for the race track, but on normal street driving?

Anyway, thanks for the explanation. I am not aware of this feature. Do you mean that even when the car stopped the engine remains at 4K RPM?.

I don't think the variance in engine RPMs can be correctly defined as "Shifting points"....remember that the CVT adjusts engine's RPM to ensure optimal delivery of power and torque at different speeds.

To me, "Shifting points" are defined as while in "Normal" mode the car upon acceleration delivers the shifting feeling of a regular Hydraullically operated 4-speed automatic changing gears from 1st, 2nd, 3rd and so on. I get no such feeling on acceleration from the car.

[Paul]

Quote:

Originally posted by cooper4us
First off, I would hate to drive a car running at 4,000 RPM and staying there all the time. Great for the race track, but on normal street driving?

Anyway, thanks for the explanation. I am not aware of this feature. Do you mean that even when the car stopped the engine remains at 4K RPM?.

I don't think the variance in engine RPMs can be correctly defined as "Shifting points"....remember that the CVT adjusts engine's RPM to ensure optimal delivery of power and torque at different speeds.

To me, "Shifting points" are defined as while in "Normal" mode the car upon acceleration delivers the shifting feeling of a regular Hydraullically operated 4-speed automatic changing gears from 1st, 2nd, 3rd and so on. I get no such feeling on acceleration from the car.

It's certainly not smooth as silk in the CVT's I've driven, you can feel a 'change' which I assume is artificially programmed, as the theory in CVT is it's constantly variable.

Not sure this is generally when bombing around, or just when you use the kick-down. Cant remember!

[ipoulin]

First off, I would love a vehicle running at 4000 and staying there once I get going; for economy, sound and enjoyment of driving. ...

My understanding of the CVT would have it rev at normal revs, only going to the constant rev amount once the vehicle is moving at a certain point (dunno the cutover)...

If I am incorrect in my assumptions to its non-US behavior, someone let me know .

-- Ian

[cooper4us]

Maybe when using the kickdown feature but otherwise I have no feeling at all during acceleration of any artificial shifting points (Unless I find my self fiddling with the steptronic).

I also have an American car with a 4-speed automatic slushbox also and in that car you can (albeit very smoothly) feel the shifting points and see them in the Tach needle as well. Not so in the Cooper CVT.

[Paul]

Quote:

Originally posted by cooper4us
Maybe when using the kickdown feature but otherwise I have no feeling at all during acceleration of any artificial shifting points (Unless I find my self fiddling with the steptronic).

I also have an American car with a 4-speed automatic slushbox also and in that car you can (albeit very smoothly) feel the shifting points and see them in the Tach needle as well. Not so in the Cooper CVT.

So to hit the limiter you have to use kick-down anyway (I believe), which envokes a 'shift' to the next range. I think this is how it works?

(Racking brain back only a couple of weeks when I actually had a CVT for a week!).

[cooper4us]

How can riding a car at 4K RPM at all times ensure better fuel economy?

The Cooper CVT uses more fuel on either SD (RPMs are kept at or above 3K RPM) or Steptronic.

[cooper4us]

Quote:

Originally posted by Paul Mullett
So to hit the limiter you have to use kick-down anyway (I believe), which envokes a 'shift' to the next range. I think this is how it works?

(Racking brain back only a couple of weeks when I actually had a CVT for a week!).

I believe you are correct there Paul. The accelerator kickdown feature simulates a sudden gear downshift for more power. In my other car if you want to induce a downshift for passing you also have to press the gas pedal a bit deeper to tell the computer that you need the tranny to make a downshift. General Motors cars in the US equipped with the 3.8L V6 engine have this feature and it works very, very well (There is no lag when "requesting" a downshift from the transmission).

[MINIsota_Cuke]

The following is text from an article in the July 17, 2001, edition of the Edmonton Journal. I think it at least partially speaks to the point that ipoulin is trying to make. (sorry it's about Audi A6)

As worthwhile as the new engine is to the A6's performance, it pales in comparison to its new multitronic transmission. Like the new Mini's powertrain, the multitronic is one of the new continuously variable transmissions (CVT) that promise to render the current crops of automatic obsolete. Like the BMW-produced Mini (and almost all snowmobiles), the Audi's transmission uses a set of pulleys and a belt (Audi's system actually uses a linked chain) to offer an almost infinite number of ratios as it completely eliminates the internal gears.

The Audi's system, however, is more sophisticated than BMW's. For one thing, the multitronic's function has been tailored for easy acceptance by North American drivers without compromising the CVT's advances in efficiency. When accelerating, traditional CVTs immediately increase rpm to a steady point (about 5,000 rpm in the Mini's case) and then increase speed by continuously varying (hence the name) its gear ratios. Because the engine's rpm is held close to its torque peak, a CVT is actually more efficient than a manual transmission. Indeed, a multitronic A6 is 0.1 seconds faster to 100 km/h than the same car equipped with a manual transmission (not available in North America).

The downside is that since the motor is held at a constant rpm, there's less sensation of acceleration - something, say both Audi and BMW, that has prevented universal acclaim for CVTs among the focus groups that have tested their cars.

Audi gets around the problem by engineering in a few attributes of a traditional automatic. Primary is that, unlike a pure CVT, the multitronic system does increase rpm as speed increases, only there's no sensation of the gear shifting. Another feature engineered in for consumer acceptance, not for efficiency, is ``creep.'' Unlike traditional automatics, a CVT will not move forward at idle when you release the brake. Because they were adamant about gaining acceptance in our conservative market, Audi's engineers actually contrived some creep into its multitronic system so that it would feel more like a normal automatic.

Whatever the compromises it's made, the multitronic is nothing short of a revolution in transmissions. For one thing, here's a put-it-in-D (for drive) transmission that actually accelerates better and gets superior fuel economy than its manual counterpart. It even feels more sporty, responding to matting of the throttle with an almost immediate increase in rpm and instantaneous acceleration. And because a CVT can offer a much wider spread of gears than a regular transmission, the multitronic's top ratio is much taller, revving the engine at only 1,700 at 100 km/h compared with the manual version's 2,600 rpm.

That's why the multitronic gets better fuel economy than the manual. It also means the multitronic-equipped A6 feels much smoother and is significantly quieter at cruising speeds.

Thought this might produce some more feedback.

[Sejanus]

Interesting. So why is fuel efficiency lower on the CVT than the 5-speed?

[nonsequitur]

I think you've sorted out the "shifting" behavior, and I'll conclude that it is exhibited worldwide from the software.

The Cooper CVT shows this shifting clearly when throttle is to the floor (past the kickdown detent) in D, SD, or Steptronic, each a little differently. If throttle is held just shy of the detent in D or SD, the engine comes up to a maximum torque rpm and holds there while the transmission manages very smooth acceleration.

Thanks for the Audi article. Interesting high-torque device from a real automotive innovator.

[PigLick]

One thing that doesn't make a lot of sense to me, though, is saying that the change to the way their CVT operates is due to the North American market. True, Americans may be more used to the feel of an old-fashioned auto, and so might feel strange with a CVT. However, I would think that the Europeans, who are much more accustomed to manual trannies, would be the ones who really disliked the super-smooth accelaration of a CVT. It's amazing how much your sense of acceleration has to do with feeling those shift points, and the shift points are much more noticeable in a manual than a "slushbox."

In my CVT, the RPMs don't remain completely constant, reving up to oine speed and then staying there, unless I'm either maintaining a relatively even speed, or very gradually accelerating/decelerating. Under rapid acceleration or deceleration, the CVT will quickly "shift" up or down to supply more/less power. This makes sense to me, however. At cruising speed, for economy reasons, you want your RPMs to be as low as reasonably possible, which means well below your peak power. When you want to accelarate, though, you want to be at your peak (or as near as possible), and you want to get there as fast as possible. So if you're cruising along then stomp on the pedal, I would expect the RPMs to very quickly jump up.

PigLick